6% Hydrogen peroxide Teeth whitening gel

We all want a brighter, whiter smile, but with whitening treatments at the dentist costing up to £750 a time, many people are turning to DIY kits.

There are plenty to choose from, with supermarket shelves literally groaning with 'whitening' products and toothpastes.

However, the British Academy of Cosmetic Dentistry (BACD) has issued a warning claiming that many DIY whiteners fail to give a good result or can even cause permanent damage to teeth.

We asked Dr Philip Stemmer, who has more than 25 years' experience with tooth whitening, to look at some of the latest DIY products. We then assessed them according to their effectiveness, safety and ease of use:

It contains ten disposable, individually wrapped, single-dose applications. Use one a day, squeezing the whitening gel into the lined, plastic trays designed to fit over your teeth.

Remove the trays, leaving the inner flexible liners filled with gel on the teeth for 30 to 60 minutes.

Dr Stemmer says: The strength of the hydrogen peroxide is comparable with some of the bleaching products used by dentists - so the whitening gel should work.

My big concern here, however, is that the gel is not applied to the teeth with a close-fitting, custom-made tray, so areas could be missed during the bleaching process or the powerful whitening gel could leak out onto the gums and into the mouth.

The danger is that this can lead to blistering and sensitivity. Verdict: Will whiten teeth but application method has potential for bleach to leach on to mouth and gums.

An intensive whitening toothpaste that promises 'whiter teeth in seven days' thanks to a 'professional cleansing ingredient which is also used by dentists'.

Brush teeth twice a day for three minutes each time with this instead of your usual toothpaste. The manufacturers recommend this product for tea, coffee and red wine drinkers as well as smokers.

A whiteness shade chart is supplied on the side of the box to help you monitor your progress.

Dr Stemmer says: This product does not contain any powerful bleaching ingredients, so it's not a whitening product in the true sense. But it does contain pumice, which has been added to give the teeth a powerful scrub and remove stains.

Pumice stone is extremely abrasive, so dentists tend to use it only occasionally - for example, to roughen the surface tooth enamel to get a filling to stick.

I would certainly not recommend that teeth should be cleaned with such a harsh product.

Combined with enthusiastic brushing, it could potentially cause significant damage to enamel or cause gums to recede, particularly if used four or five times a year as recommended. Verdict: It will remove stains, but it is too abrasive.

This paste will not bleach teeth - it will only remove stains. Its low abrasion formula is important and there is evidence to show that baking soda can help to remove stains from teeth.

Baking soda is a safe ingredient to find in toothpaste.

Verdict: It won't whiten teeth, but it is a good toothpaste to use to keep discolouration at bay.

THE SMILE PLACE SYSTEM

The Smile Place Teeth Whitening System, £99 plus P&P (0800 0857 145; smileplace.co.uk) A mail order 'professional and safe tooth-whitening system at an affordable price, ' say the manufacturers.

Customers first receive the putty to make impressions of their teeth. The impressions are then returned to the Smile Place for bespoke dental trays to be made.

The dental trays are sent back with a carbamide peroxide-based whitening gel - there are three strengths available, chosen according to the sensitivity/ discolouration of your teeth.

You wear the trays filled with the gel for two hours daily until the required results are achieved.

Dr Stemmer says: In an ideal world, this kit could work well because carbamide peroxide is an effective whitener.

But the customer is expected to be able to make his or her own accurate teeth impressions and assess the sensitivity of their teeth and level of discolouration, then choose the strength of bleach they require - which could potentially lead to problems.

At least the kit contains enough putty to make a second set of teeth impressions if you mess up the first.

Verdict: Could work well, but a great deal of care is needed when making the tooth impressions and choosing and using the correct strength of whitening gel.